Not foundations or cellars, but deliberately shaped underground chambers, beehive in form, connected by tunnels, and almost certainly invisible from the surface above them. This is a souterrain, a type of underground stone-built passage or chamber commonly associated with early medieval ringforts in Ireland, likely used for storage, refuge, or both. What makes Lisnaboy quietly remarkable is how thoroughly it has disappeared, at least from view.

The site sits within a ringfort, the circular earthwork enclosure that was the typical farmstead of early medieval Ireland. In 1937, a researcher named Broker documented several underground beehive chambers here, a detail that suggests a more elaborate construction than the simple linear tunnels found at many comparable sites. Beehive chambers, corbelled into domed spaces using carefully layered stone, required skill and intention to build. Yet by the time anyone looked again, there was no visible surface trace remaining. The ringfort itself presumably still defines the landscape in some form, but the souterrain beneath it had become entirely subterranean in every sense. More recently, local accounts suggest that quarrying adjacent to the site exposed an underground tunnel, which is both a loss and an accidental revelation. It is the kind of discovery that arrives too late and too casually, a glimpse of something substantial before the ground closes over it again.